I see so many! Dogmeat, Rex, molerats, geckos, raiders (Pitt raiders and fiends included), the Legion, trogs, mirelurk king, mr. handy, protectron, Y-17 trauma harness, robobrain, DEATHCLAW, East and West coast Super Mutants (including nightkin), ghost people, enclave, BoS, Pint-Sized Slasher, NCR ranger, non-feral ghoul, Jodhua Graham, Lanius... eevn the goddamn Mysterious Stranger.
Oh, and the Lone Wanderer, naturally. I don't know how many I missed though, haha.